Using method of qualitative theory of ordinary differential equation, studies economic harvesting model with variable price and cost for a single population.
利用常微分方程定性理论的方法讨论了价格成本变化的单种群经济捕获模型。
In addition, this research has analyzed the influence of population statistic variable on each factor.
此外，本研究分析了人口统计变量对于各因素的影响。
The craftsmen's family and its population, the important variable of the family scale, needs further discussing, which is beneficial for a study of farmers' family scale.
工匠家庭和人口是当时家庭规模的一个重要变量，对其进行必要的讨论，对于研究农民家庭规模有一定裨益。
There was aggregation of variable cardiovascular risk factors in this population.
各种心血管危险因素在该人群中有聚集现象。
Using computer simulating technique and cohort conception, the simulation model of armyworm population dynamics under variable temperatures was built.
应用计算机模拟技术，引入同龄组的概念，建立了适合于估测变温条件下粘虫种群动态的计算机模拟模型。
In this paper, on the basis of structural regression models the estimation of the population-averaged treatment effects is given when the response variable is a multi-dimensional vector.
在可交换条件下，当响应变量为多维时，利用结构回归模型研究总体平均处理效应的估计。
The paper proposes new separate ratio estimators for population mean using known skewness coefficient of auxiliary variable in stratified random sampling.
本文在分层随机抽样下通过使用辅助变量的偏斜系数提出了几个总体均值的估计。
The paper proposes new separate ratio estimators for population mean using known skewness coefficient of auxiliary variable in stratified random sampling.
本文在分层随机抽样下通过使用辅助变量的偏斜系数提出了几个总体均值的估计。
应用推荐